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Biomedical subjects

S Hampton

Publications and source records attributed to S Hampton.

At least 19 recordsLinked to original sources
PubMed2000

Hyperproinsulinaemia in elderly subjects: evidence for age-related pancreatic beta-cell dysfunction.

We investigated whether pancreatic beta-cell dysfunction has a role in the pathogenesis of glucose intolerance in the elderly by comparing plasma glucose, immunoreactive insulin, C-peptide and proinsulin concentrations during a 100-g oral glucose load in six healthy older male volunteers [aged 69 (65.9-74.9) years; median (95% confidence limits)] and seven young male controls [aged 24.0 (21.9-26.3) years]. Fasting and integrated concentrations of glucose and C-peptide were similar in the elderly and young. Although fasting, insulin and proinsulin levels were similar, integrated insulin (P=0.05) and proinsulin (P<0.05) concentrations were higher in the elderly than in controls. Insulin resistance, measured as homeostasis model assessment, was greater (P<0.05) in the elderly than in controls. Elderly men had greater molar ratios of integrated insulin:C-peptide (P<0.05) and proinsulin:C-peptide (P<0.01) but their respective fasting molar ratios were similar when compared with controls. Pancreatic beta-cell secretion in older subjects, as assessed by C-peptide concentrations, was inappropriately low in the presence of insulin resistance. Their post-prandial 'hyperinsulinaemia' is probably due to a combination of hyperproinsulinaemia and reduced metabolic clearance of insulin. Older subjects had disproportionately high proinsulin to C-peptide levels, suggesting pancreatic beta-cell dysfunction. These results are consistent with the notion that decreased insulin sensitivity and pancreatic beta-cell dysfunction may predispose the elderly to glucose intolerance.

Adult↗
PubMed1999

Cochlear implantation following temporal bone fracture.

Seven cases of profound hearing impairment following either unilateral or bilateral temporal bone fracture are presented who were implanted with the Nucleus 22 channel or Ineraid devices. Six patients suffered bilateral temporal bone fractures. One patient had prior congenital unilateral profound hearing impairment. This patient suffered a unilateral temporal bone fracture. Six patients became regular users of their implants. One gained little benefit and became a non-user. Two of the regular users experienced facial nerve stimulation, which could not be programmed out. In these two cases the implant was removed and the contralateral ear successfully implanted. Implant-aided audiometry demonstrated a hearing threshold of 40-50 dB at nine months after switch-on. The reliability of computed tomography (CT) scanning in predicting cochlear patency in cases of temporal bone fracture will be discussed. The benefit of complimentary imaging with magnetic resonance (MR) is highlighted.

Adolescent↗
PubMed1999

Proinsulin and insulin responses to a mixed meal in hypertriglyceridaemic men.

AIM: To investigate the contribution of proinsulin to the "hyperinsulinaemia" of hypertriglyceridaemia. METHODS: Plasma glucose, triglyceride, immunoreactive insulin, and intact proinsulin concentrations were measured before and after a mixed meal in 11 hypertriglyceridaemic men and six healthy normotriglyceridaemic male controls. RESULTS: Hypertriglyceridaemic subjects had greater fasting (101 v 50 pmol/l) and integrated (139 v 81 x 0(-3) pmol/l/h) insulin concentrations than controls. Fasting and integrated glucose and proinsulin concentrations were similar in the two groups. CONCLUSIONS: Proinsulin does not contribute to the hyperinsulinaemia observed in hypertriglyceridaemic subjects and is therefore unlikely to contribute to the increased cardiovascular risk associated with hypertriglyceridaemia.

Adult↗
PubMed1998

Extraocular light exposure does not suppress plasma melatonin in humans.

Light affects the circadian axis in at least two ways. It can cause the acute suppression of pineal melatonin synthesis, and/or a phase-shift of the circadian oscillator. As recent evidence has suggested that extraocular light exposure may cause phase-shifts of the circadian clock, we have investigated whether suppression of melatonin can be induced by the same type of light exposure. In the first study subjects' eyes were exposed to white light (2250 lux for 30 mins) via a fibre optic cable. As expected, suppression of nighttime plasma melatonin levels (61 +/- 6%) was observed. In the second study, light of the same quality but higher intensity (14,000 or 67,500 lux for 180 mins) was delivered in the same manner to the popliteal region behind the subjects' knees, whilst shielding their eyes. No suppression of plasma melatonin levels (4 +/- 7%) was detected in any of the subjects. Thus, extraocular photoreception, if it exists in mammals, does not affect the suprachiasmatic nucleipineal pathway.

Adolescent↗
PubMed1998

Bandage application.

The application of external compression is known to be an effective treatment for venous ulcers and the skills required to provide adequate pressure depend on the type of compression to be applied. Holistic assessment of the patient, along with education of the practitioner, leads to safe application of compression bandages. Incorrectly applied bandages can cause an increase in the size of the ulcer and may lead to amputation if used on ischaemic limbs1.

Bandages↗
PubMed1998

Effects of the endogenous clock and sleep time on melatonin, insulin, glucose and lipid metabolism.

This study was undertaken to determine whether the internal clock contributes to the hormone and metabolic responses following food, in an experiment designed to dissociate internal clock effects from other factors. Nine female subjects participated. They lived indoors for 31 days with normal time cues, including the natural light: darkness cycle. For 7 days they retired to bed from 0000 h to 0800 h. They then underwent a 26-h 'constant routine' (CR) starting at 0800 h, being seated awake in dim light with hourly 88 Kcal drinks. They then lived on an imposed 27-h day (18 h of wakefulness, 9 h allowed for sleep), for a total of 27 days. A second 26-h CR, starting at 2200 h, was completed. During each CR salivary melatonin and plasma glucose, triacylglycerol (TAG), non-essential fatty acids (NEFA), insulin, gastric inhibitory peptide (GIP) and glucagon-like peptide-1 (GLP-1) were measured hourly. Melatonin and body temperature data indicated no shift in the endogenous clock during the 27-h imposed schedule. Postprandial NEFA, GIP and GLP-1 showed no consistent effects. Glucose, TAG and insulin increased during the night in the first CR. There was a significant effect of both the endogenous clock and sleep for glucose and TAG, but not for insulin. These findings may be relevant to the known increased risk of cardiovascular disease amongst shift workers.

Adult↗
PubMed1997

Elevated post-prandial gastric inhibitory polypeptide concentrations in hypertriglyceridaemic subjects.

1. We investigated whether abnormalities of gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (7-36 amide) (GLP-1) contribute to the hypertriglyceridaemia and hyperinsulinaemia in hypertriglyceridaemic subjects. Serum triglycerides and plasma glucose GIP, GLP-1 and immunoreactive insulin (IRI) concentrations were measured before and after a mixed meal in 15 hypertriglyceridaemic patients and in eight healthy normotriglyceridaemic control subjects. 2. Integrated post-prandial GIP concentrations were greater than in controls (P < 0.05) and correlated positively with both fasting and integrated post-prandial triglyceride concentrations (P < 0.05 for both). Fasting and integrated post-prandial IRI levels were higher in hypertriglyceridaemic subjects than in controls (P < 0.02 and P < 0.05 respectively) and correlated positively with fasting triglycerides (P < 0.02 and P < 0.001 respectively) and integrated post-prandial triglycerides (P < 0.005 and P < 0.05 respectively). There was no correlation between GIP concentrations and either fasting or post-prandial IRI levels. Fasting and post-prandial concentrations of GLP-1 were similar in patients and controls. 3. Hypertriglyceridaemic subjects have post-prandial hyperGIPaemia in addition to the well-documented hyperinsulinaemia. We found no association between GIP and insulin. There is, however, clear evidence for an association between post-prandial GIP concentrations and triglyceride levels. We suggest that this association may depend on changes in lipoprotein lipase activity and that there may be a feedback loop between GIP and triglyceride lipolysis.

Adult↗
PubMed1997

Reliability in reporting pressure sore incidence.

Encouraging the accurate reporting of pressure sores can be a difficult task. A telephone line for recording details on pressure damage may help to encourage reporting. An organisation-wide protocol for tackling pressure sores is needed.

Data Collection↗
PubMed1997

Wound assessment.

Wound healing will not be achieved if a wound management product is inappropriate for an individual patient. An holistic approach using a nursing model is required to assess the needs of the patient and the wound.

Holistic Nursing↗
PubMed1996

The entero-insular axis in polycystic ovarian syndrome.

We investigated the contributions made by the entero-insular axis, proinsulin and the fractional hepatic extraction of insulin to the hyperinsulinaemia characteristic of polycystic ovarian syndrome (PCOS). We measured plasma glucose, gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (7-36 amide) (GLP-1(7-36) amide), immunoreactive insulin (IRI), intact proinsulin (IPI), and C-peptide concentrations during a 75 g oral glucose tolerance test in seven normal weight women with PCOS and eight healthy women. Women with PCOS had higher fasting (P = 0.05) and integrated (P < 0.01) IRI concentrations than controls. Fasting C-peptide levels were similar in both groups but integrated C-peptide (P < 0.05) concentrations were greater in PCOS subjects than controls. Fasting and integrated concentrations of glucose, GIP and GLP-1(7-36) amide were similar in subjects with PCOS and controls. Although fasting IPI concentrations were similar in both groups, integrated IPI concentrations were higher (P = 0.05) in patients with PCOS. Women with PCOS had similar fasting but higher (P < 0.05) integrated IRI:C-peptide molar ratios than controls. Fasting and integrated IPI:IRI molar ratios were similar in both groups. These results confirm that lean women with PCOS have peripheral hyperinsulinaemia. The mild fasting hyperinsulinaemia is due to increased pancreatic secretion, whereas the stimulated hyperinsulinaemia is due to both pancreatic hypersecretion and reduced fractional hepatic extraction of insulin. Hyperproinsulinaemia is modest and appropriate in PCOS, GIP and GLP-1(7-36) amide do not contribute to the stimulated hyperinsulinaemia in PCOS.

Adult↗
PubMed1995

Melatonin and adjustment to phase shift.

The pineal hormone melatonin has clear circadian phase-shifting effects in humans which have recently been formalized as a phase response curve. Its potential use in circadian rhythm disorders has been investigated in field studies of jet lag and shift work and in simulated phase shift. A substantial amount of information indicates that in the majority of subjects it hastens adaptation of both subjective and objective measures to forced shifts in time cues with few reported side-effects. Field studies of its use in adaptation to shift work are sparse and preliminary but the first indications are positive. In some blind subjects with sleep disturbance it can stabilize sleep onset time without necessarily entraining all circadian rhythms and it can advance sleep timing in delayed sleep-phase insomnia. Acute suppression of core body temperature may be an integral part of the phase-shifting mechanism.

Journal Article↗
PubMed1995

Rearfoot posture in subjects with patellofemoral pain.

The relationship between structural foot deformities and excessive subtalar joint pronation as being contributory to patellofemoral pain has not been well documented. It was the purpose of this study to assess the rearfoot posture in patients diagnosed with patellofemoral pain compared with a normal population. In addition, the intratester reliability in obtaining rearfoot measurements was assessed for right and left sides in 21 normal subjects. A goniometer was used to measure rearfoot posture in 30 female subjects (15 with patellofemoral pain and 15 controls). Measurements were taken with the subjects prone and the subtalar joint in neutral. Intraclass correlation coefficients were good for both the right and left measurements (.87 and .86, respectively). A small but significant increase in rearfoot varus was found in the patellofemoral pain group compared with the control group (8.9 vs. 6.8 degrees; p = .0002). These results suggest that increased rearfoot varus may be a contributing factor in patellofemoral pain and should be assessed when evaluating the events at the subtalar joint and the lower extremity. In addition, it has been demonstrated that consistent rearfoot measurements can be obtained by an individual clinician.

Adult↗
PubMed1994

Early identification and remediation of phonological-processing deficits in first-grade children at risk for reading disabilities.

The present study assessed 486 first-quarter first graders on their reading and phonological-processing skills and intelligence. Based on this assessment, and using the classification data from Hurford et al.'s (1993) study, 99 children were identified as being at risk for reading difficulties: 53 children at risk for reading disabilities (RD) and 46 children at risk for becoming "garden-variety" poor readers (GV). Half of the RD and GV groups received the phonological-processing intervention. Posttraining assessment indicated that the training procedure not only was effective in increasing the phonological-processing skills of the trained participants, but also increased their reading ability. Both of the RD and GV trained groups benefited from the training. Analyses also indicated that the initial screening device was somewhat less accurate in the present study in identifying at-risk children than in our previous studies (85% vs. approximately 98%, respectively). The results of the present study indicate that it is possible to identify children at risk for reading difficulties and to significantly improve their phonological-processing and reading abilities.

Child↗